Described in prior patent applications cited above of two of the applicants herein, Leonard Storch and Ernst van Haagen, is a new and improved bar code structure called binary coded binary, BCB. BCB cannot realize its performance potential when decoded by common present day bar code decoding processes, methods and devices such as the type of reference decode algorithm systems published and described in AIM's (AIM Incorporated is an industry trade association based in Pittsburgh, Pa., Automatic Identification Manufacturers) Uniform Symbology Specifications (USS), .COPYRGT.1993 (copies filed herewith) and elsewhere.
What has now been invented by the applicants are new bar code decode processes, methods and devices that incorporate, for example, a moving average, and begin to realize BCB's decode performance potential, including, for example: improved ability to handle extreme levels of ink spread and ink shrink distortion, the limit becomes the point where the sensing apparatus cannot resolve narrow bar code elements; and, improved ability to handle apparent and actual random edge dislocation distortion (systematic, every edge affected), referred to by applicants as edge noise; as well as improved ability to handle apparent and actual occasional greater-amplitude random edge dislocation distortion (non-systematic, occasional edges affected), referred to by applicants as edge spikes.
As it turns out, applicants' new bar code decode processes, methods and devices invented and disclosed in this present application for BCB, can also be used to decode other linear bar codes, including, by way of example, UPC, Code 128 and Code 93; UPC, Code 128 and Code 93 symbols can be decoded exactly as they are now printed. Codabar, Code 39 and Interleaved 2-of-5 can also be decoded by applicants' new decoder if they are printed using whole multiples of modules and no fractional ratios for narrow and wide elements, for example, ratios of 2:1 exactly or 3:1 exactly can be made to work with applicants' new decoder. (A module is defined by AIM as: "The narrowest nominal width unit of measure in a symbol. One or more modules are used to construct an element.") Codabar and Code 39 are discrete (not continuous) and therefore have intercharacter gaps; the intercharacter gaps must also be printed using whole multiples of modules if applicants' new decoder is to decode them with maximum accuracy.
One benefit using applicants' new decoder inventions for UPC, for example, is that the well-known 1-7 and 2-8 UPC character substitution problems can be avoided altogether (this has been a much sought after holy grail for serious bar code enthusiasts). Applicants' present inventions may be used for these and other popular (linear) bar codes, as well as for various two dimensional (2D) bar codes, such as Code 16K, Code 49, PDF 417 and others, in order to increase reading system accuracy and output productivity when high levels of ink spread, edge noise and other distortions are present. (Bar code elements in a linear bar code are disposed along one line, and in a 2D bar code the elements are disposed along two or more lines.)
Applicants also disclose novel means to precisely distort pristine bar code symbol timing count data, and means to simulate bar code decoding on computer apparatus. This, for the first time, allows controlled meaningful comparisons between different decoding processes and methods as well as between different bar code symbologies. The bar code industry was estimated in 1992 to be over $5 billion, and growing toward $20 billion by the turn of the century, yet, as of this patent filing, mean time between bar code failure data and related data is nonexistent, and worse, empirical data gleaned from various elaborate bar code reading tests conducted during the last decade is misleading. Applicants' distortion and simulation apparatus, processes and methods will allow such valuable data to become an integral part of this booming new automatic identification industry.